The present invention relates generally to dust or chip collection systems for saws or other power operated equipment or machinery. More particularly, the invention relates to such dust or chip collection systems with the dust collector being disposed on a movable portion of the saw or other such equipment in order to maintain proper dust-collecting alignment with a movable saw blade or other work-performing device while performing various operations on a workpiece.
Saws and other apparatuses designed for cutting or performing other working operations on a workpiece frequently require a saw blade, cutter, or other such work-performing device that is movable to a number of different positions or orientations for performing various operations. Examples of such equipment include compound miter saws, which allow the user to selectively move the saw blade into any of a number of positions or modes for square cutting, for miter cutting, for bevel cutting, or for compound cutting where a combination miter and bevel are cut. In addition, some operations, such as shaping or dado cutting operations, for example, require the use of saw blades or other cutting devices of different shapes or sizes to be substituted for one another in order to perform the desired operation on the workpiece, whether the workpiece is composed of wood, plastic, metal, or other materials. In most examples of such equipment, it is highly desirable to provide a dust collection system for diverting dust and chips away from the user.
In order to accommodate these widely varied working operations, dust collection ducts, or openings are frequently disposed on an adjustable guard so as to be at least partially adjustable for various operations, or on a fence in order to accommodate the varied positions or orientations of the blade or other cutter. If such dust collector adjustability, by way of adjustment of the guard, were not provided, a substantial loss of dust-collecting effectiveness would result, or a very large dust collection opening would have to be provided in order to accommodate the widely varying range of movement, position, or size of the saw blade, cutter, or other working device. Such collection ducts or openings on guards or fences have been found to be relatively ineffective in many of their adjusted positions, and such large collection openings have been found to be cumbersome and disadvantageous because of the space occupied by them.
In an attempt to address the above-discussed problems, a variety of other dust collection arrangements have previously been provided. However, many of such prior arrangements have suffered the same or other disadvantages, including difficulty in maintaining proper alignment between the dust collection duct or opening and the saw blade or other cutter, inconvenience and interference when performing operations on large or odd-shaped workpieces, the possibility of inadvertently misplacing separate dust collection components, lack of adequate dust collection, or other similar short-comings. Thus, the need has arisen for a dust collection system for compound miter saws, or other power equipment with movable or adjustable blades or cutters, which overcomes these disadvantages, as well as providing greater dust-collection effectiveness, improved ease of operation, economy in manufacturing, and other advantages that will become readily apparent to those skilled in the art from the discussion below.
In accordance with the present invention, an improved dust collection system for a saw or other device having a movable blade or cutting tool is provided. The dust collection system is spaced away from the saw blade or other cutting tool, is separate from any blade or cutter guard, and includes a dust-receiving opening that is at a fixed location relative to the movable blade or cutting tool and movable therewith. Preferably, the dust-receiving opening has an orientation relative to the blade or cutting tool that is aligned with a line that extends between the opening and the blade or cutting tool, with such line extending along a tangent to the rotation of the blade or cutting tool, and with such tangent preferably being at a location on the blade or cutting tool that engages the workpiece when the blade or cutting tool is moved to a workpiece-engaging position. Such dust collection opening orientation thus remains essentially constant during movement of the blade or cutting tool and is independent of any adjustment of the guard.
In preferred embodiments of the present invention for compound miter saws, for example, the dust-receiving opening is disposed at the open end of a dust duct that is interconnected with a pivot mechanism that is adapted for pivotally moving the saw blade into and out of engagement with a workpiece and for pivotally moving the saw blade among various cutting configurations. Such preferred dust duct is pivotally movable with a pivot arm and is preferably disposed in a bifurcated portion of the pivot arm in a space between a pair of spaced-apart legs. The dust duct is adapted for conveying dust or chips away from the saw and the user and can be connected in dust-conveying communication with a dust collection receptacle, either with or without powered dust extraction or dust-conveying vacuum equipment.
Additional objects, advantages, and features of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings.